Regular HIV Testing among At-risk Latino Men This R34 application proposes 3 years of research to pilot an intervention to promote regular HIV testing and safer behavior among sociocentric networks of Latino men at risk for HIV. In the US, 20% of the 1.1 million individuals living with HIV are unaware of their HIV status. Undiagnosed HIV positive persons cannot benefit from early access to treatments that increase quality of life and reduce infectivity. Encouraging HIV testing and providing treatment to those testing positive can improve the health of HIV infected persons and reduce HIV incidence. To obtain the benefits of early diagnosis, CDC suggest that persons at higher risk for HIV get tested regularly twice a year. Despite the many strategies to encourage HIV testing, to our knowledge, there are no strategies to promote regular HIV testing among any group at risk for HIV. In the US, the HIV epidemic is largely concentrated in clusters of individuals with high HIV prevalence and undiagnosed infections. Latino men who have sex with men (LMSM) comprise many of these clusters. LMSM experience challenges that make it difficult to engage them in preventive care, including disconnection from services, norms than condemn homosexuality, and erroneous risk assessments such as the belief that sex within their ingroup is less risky. LMSM rely on other LMSM who are sources of advice and partially shield them from the double jeopardy of being a sexual and ethnic minority. Network approaches can use these relationships to reach high risk LMSM and foster norms that reduce their collective risk. This proposal intends to use networks to promote regular HIV testing and risk reduction among LMSM. We will recruit three-ring networks of LMSM and identify their ties. Well positioned LMSM will inform and motivate their peers for risk reduction, and be trained to be bridges to prevention resources, provide tailored prompts to testing, and reward HIV testing behaviors to encourage repetition. This proposal seeks to (1) conduct research to tailor recruitment and intervention procedures to networks of LMSM, (2) demonstrate the feasibility of recruiting 3-ring sociocentric networks of LMSM, train key members to promote regular testing and risk reduction in their networks, and assess network characteristics and outcomes at six- and 12-month follow up; and (3) evaluate the acceptability of the intervention among participants. Following formative work, we will invite socially central LMSM to initiate recruitment of five three- ring networks of LMSM (N H 150). We will test men for HIV and recommend that they get tested regularly. We will invite key members of three randomly selected networks to a six-session training to promote regular HIV testing and risk reduction in their networks. We will assess networks and intervention outcomes at six- and 12- month follow-ups. At the last follow up, we will interview participants to elicit their experiences and identify effective communication strategies. This study will evaluate the feasibility of a strategy to promote regular testing and risk reduction among networks that account for a large number of new HIV cases. If successful, this project will inform a randomized trial with an 18-month follow up to evaluate the efficacy of this approach.